Sound insulation for quiet vehicles cuts down on ‘noise events’

It is probably not a cause for much controversy to suggest sound insulation for loud vehicles in order to create less of a disturbance for fellow road users or for residents who live close to a main traffic route.

But in measuring disturbances due to passing vehicles, it is not necessarily the specific volume of the individual vehicle that matters; instead, it can be more about the relative engine noise compared to the background level of traffic noise overall.

In this context, even a quiet vehicle can create a significant disturbance, or ‘noise event’, when passing along a road that has particularly low levels of traffic, or which for any reason happens to mostly serve quieter vehicles.

A paper presented at Acoustics 2016 by a team from Griffith University in Australia and Ghent University in Belgium explains this distinction in more detail.

“A noise event in the sound from a stream of road traffic is a discrete component of the sound signal that stands out, or emerges, from the rest of the signal generated by the traffic stream,” they write.

“It is most often the result of the passage of an individual loud vehicle, or succession of vehicles, or even the passage of a not particularly loud vehicle heard against a quieter background in situations of low traffic flow.”

This relative nature of disturbance due to traffic noise – especially for people who are trying to sleep – makes sound insulation for quiet vehicles as important in low-traffic areas as it is for louder vehicles, to ensure that the overall background noise level remains as low as possible at all times.